Chromium plating is often used to provide a hard, durable, corrosion resistant and/or decorative finish to a platable substrate. Such plating typically involves the use of a chromic acid plating solution from which chromium is deposited on to a cathodic substrate as a result of an electrolytically induced oxidation-reduction reaction.
During the plating process, there is evolution of hydrogen gas at the anode and oxygen gas at the cathode, i.e., the substrate. The evolution of these gases carries a fine spray or mist of chromium plating solution into the atmosphere around the plating tank. Contact with the chromic acid mist may cause severe irritation to the mucous membranes and/or skin lesions. Moreover, chromium has been identified as a suspected carcinogen.
A variety of methods have been developed to deal with the mist generated during chromium plating. Such methods include collecting the mist above the tanks using fume hoods, then scrubbing the mist with various types of fume scrubbers. However, there is a great volume of air around the plating tank which contains the mist. Some mist remains uncollected and untreated by conventional methods and escapes into the atmosphere.
Accordingly, there is a need for a simple, more efficient way to reduce the amount of chromium mist which escapes to the atmosphere during chrome plating.